Amongst the estimated eight thousand (8,000) endemic plants of the Iberian peninsular there are plants worthy of inclusion in the Mediterranean garden, but please do not collect those plants from the wild. Photograph what you see in it's natural habitat and then source your plants from reputable sources. If you can not identify a plant somebody on the Internet will be only too pleased to help you
Semi arid poor and stony soil can be easily washed away by the infrequent though often torrential rains that fall on the Spanish peninsula. Even on those hot summer days flash storms can wash away trees, embankments and street furniture. Watch the news broadcasts on Spanish television to see how wide spread and devastating the damage can be. Terraced walls can be undermined in an hour by the rains, and your carefully nurtured garden or orchard can wash away before your eyes. Try to use the rain running off the land by channelling it away from fragile areas to where you need it most if you can collect it for reuse so much the better.
If you dot your plants around your garden leaving vast tracts of bare soil, you will find that the soil will rapidly dry out making your plants weaker and therefore prone to the effects of plant disease or infestation by insect attacks. Plant your plants closer together and protect the exposed earth with a mulch of composted material or even stones and you will minimise water loss to the atmosphere. The shade afforded to the ground by the leaf canopy of the growing plants will create a micro-climate in your garden in which your plants will prosper. Look out for seedlings between the older plants, they will enable you to regenerate the older specimens and keep your garden fresh.
An important consideration to the land conservation in Spain is the clearing of debris from the land. Fire here can spread quickly with horrendous and sometimes fatal results. Endemic plants like the Cistus and those useful aromatic herbs are filled with flammable oils; those hot summer winds and the lightening strike are enough to start a wild fire. Barbecue and camp fires add to the risk of such events happening. I have seen wild fires burning on three sides of my property, even though the fire fighters and local authorities managed them well, acres of native forests were lost.
Much of the debris that you clear up around your plot can be composted in your own garden. Anything else that you feel you are unable to recycle, can be placed in the plant waste receptacle provided in each village for commercial composting.